I decided to compare for myself, based on the recommendations others made to look at the Dell XPS M1530. I started by selecting the base model at $999 and configuring it as close as possible to the base model MacBook Pro. The only addition I made to the MBP was to upgrade to a 250GB HDD, so I could match up storage capacity. My goal was to make 2 machines with specs as closely matched as possible here and compare the cost.
Here's the Dell breakdown.. Starts at $999.
1. CPU - Upgrade to T8300 2.4 Ghz C2D +$175
2. OS - Upgrade to Vista Ultimate +$150
3. Screen - Upgrade to 1440x900 LED backlit display +$125
4. Memory - both systems have 2GB DDR2 667 Mhz FSB, so no change
5. HDD - Upgrade to 250GB with motion sensor (The MBP has a motion sensor too) +$250
6. Optical - Both systems have a DVD+/-RW, so no change
7. Video - Upgrade to Nvidia 8600M GT 256MB (same as MBP) +$100
8. WLAN - Upgrade to Dell 1505 Wireless-N +$25
9. Mobile broadband - skipped
10. Bluetooth - Upgrade to internal BT 2.0+EDR +$20
11. Battery - No change, as they'r roughly the same capacity (56 vs 60 WHr)
12. Modem - skip, neither has a modem
13. Audio - standard HD Audio
14. Media Apps - Add Adobe Premiere Elements (MBP has iMovie/iDVD) +$79
15. No Games/Gaming Accessories/Hot Deals/Laptop Bags/External Mouse/external storage/speakers/networking accessories/tv tuners/extra power stuff/top selling sw/
16. Warranty - kept standard, since they match.
17. No further options
Total price on this Dell XPS M1530, configured to match the base MacBook Pro? $1923. The base cost on the MBP was $1999 + $50 to move up to a 250GB HDD, for a total of $2049. Total cost difference $126, or a 6.5% premium.
Any time I can pay less than 7% more for a computer that lets me run Mac OS X instead of Windows Vista, sign me up.